/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.objectweb.asm;

/**
 * A reference to a field or a method.
 *
 * @author Remi Forax
 * @author Eric Bruneton
 */
public final class Handle {

    /**
      * The kind of field or method designated by this Handle. Should be {@link Opcodes#H_GETFIELD},
      * {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC}, {@link
      * Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL},
      * {@link Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
      */
    private final int tag;

    /** The internal name of the class that owns the field or method designated by this handle. */
    private final String owner;

    /** The name of the field or method designated by this handle. */
    private final String name;

    /** The descriptor of the field or method designated by this handle. */
    private final String descriptor;

    /** Whether the owner is an interface or not. */
    private final boolean isInterface;

    /**
      * Constructs a new field or method handle.
      *
      * @param tag the kind of field or method designated by this Handle. Must be {@link
      *     Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link
      *     Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
      *     {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or {@link
      *     Opcodes#H_INVOKEINTERFACE}.
      * @param owner the internal name of the class that owns the field or method designated by this
      *     handle (see {@link Type#getInternalName()}).
      * @param name the name of the field or method designated by this handle.
      * @param descriptor the descriptor of the field or method designated by this handle.
      * @deprecated this constructor has been superseded by {@link #Handle(int, String, String, String,
      *     boolean)}.
      */
    @Deprecated
    public Handle(final int tag, final String owner, final String name, final String descriptor) {
        this(tag, owner, name, descriptor, tag == Opcodes.H_INVOKEINTERFACE);
    }

    /**
      * Constructs a new field or method handle.
      *
      * @param tag the kind of field or method designated by this Handle. Must be {@link
      *     Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link
      *     Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
      *     {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or {@link
      *     Opcodes#H_INVOKEINTERFACE}.
      * @param owner the internal name of the class that owns the field or method designated by this
      *     handle (see {@link Type#getInternalName()}).
      * @param name the name of the field or method designated by this handle.
      * @param descriptor the descriptor of the field or method designated by this handle.
      * @param isInterface whether the owner is an interface or not.
      */
    public Handle(
            final int tag,
            final String owner,
            final String name,
            final String descriptor,
            final boolean isInterface) {
        this.tag = tag;
        this.owner = owner;
        this.name = name;
        this.descriptor = descriptor;
        this.isInterface = isInterface;
    }

    /**
      * Returns the kind of field or method designated by this handle.
      *
      * @return {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD},
      *     {@link Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link
      *     Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL}, {@link
      *     Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
      */
    public int getTag() {
        return tag;
    }

    /**
      * Returns the internal name of the class that owns the field or method designated by this handle.
      *
      * @return the internal name of the class that owns the field or method designated by this handle
      *     (see {@link Type#getInternalName()}).
      */
    public String getOwner() {
        return owner;
    }

    /**
      * Returns the name of the field or method designated by this handle.
      *
      * @return the name of the field or method designated by this handle.
      */
    public String getName() {
        return name;
    }

    /**
      * Returns the descriptor of the field or method designated by this handle.
      *
      * @return the descriptor of the field or method designated by this handle.
      */
    public String getDesc() {
        return descriptor;
    }

    /**
      * Returns true if the owner of the field or method designated by this handle is an interface.
      *
      * @return true if the owner of the field or method designated by this handle is an interface.
      */
    public boolean isInterface() {
        return isInterface;
    }

    @Override
    public boolean equals(final Object object) {
        if (object == this) {
            return true;
        }
        if (!(object instanceof Handle)) {
            return false;
        }
        Handle handle = (Handle) object;
        return tag == handle.tag
                && isInterface == handle.isInterface
                && owner.equals(handle.owner)
                && name.equals(handle.name)
                && descriptor.equals(handle.descriptor);
    }

    @Override
    public int hashCode() {
        return tag
                + (isInterface ? 64 : 0)
                + owner.hashCode() * name.hashCode() * descriptor.hashCode();
    }

    /**
      * Returns the textual representation of this handle. The textual representation is:
      *
      * <ul>
      *   <li>for a reference to a class: owner "." name descriptor " (" tag ")",
      *   <li>for a reference to an interface: owner "." name descriptor " (" tag " itf)".
      * </ul>
      */
    @Override
    public String toString() {
        return owner + '.' + name + descriptor + " (" + tag + (isInterface ? " itf" : "") + ')';
    }
}
